This file documents the installation of the GNU compiler. Copyright
(C) 1988, 1989, 1992, 1994, 1995 Free Software Foundation, Inc. You
may copy, distribute, and modify it freely as long as you preserve this
copyright notice and permission notice.
Installing GNU CC
*****************
Here is the procedure for installing GNU CC on a Unix system. See
*Note VMS Install::, for VMS systems. In this section we assume you
compile in the same directory that contains the source files; see *Note
Other Dir::, to find out how to compile in a separate directory on Unix
systems.
You cannot install GNU C by itself on MSDOS; it will not compile
under any MSDOS compiler except itself. You need to get the complete
compilation package DJGPP, which includes binaries as well as sources,
and includes all the necessary compilation tools and libraries.
1. If you have built GNU CC previously in the same directory for a
different target machine, do `make distclean' to delete all files
that might be invalid. One of the files this deletes is
`Makefile'; if `make distclean' complains that `Makefile' does not
exist, it probably means that the directory is already suitably
clean.
2. On a System V release 4 system, make sure `/usr/bin' precedes
`/usr/ucb' in `PATH'. The `cc' command in `/usr/ucb' uses
libraries which have bugs.
3. Specify the host, build and target machine configurations. You do
this by running the file `configure'.
The "build" machine is the system which you are using, the "host"
machine is the system where you want to run the resulting compiler
(normally the build machine), and the "target" machine is the
system for which you want the compiler to generate code.
If you are building a compiler to produce code for the machine it
runs on (a native compiler), you normally do not need to specify
any operands to `configure'; it will try to guess the type of
machine you are on and use that as the build, host and target
machines. So you don't need to specify a configuration when
building a native compiler unless `configure' cannot figure out
what your configuration is or guesses wrong.
In those cases, specify the build machine's "configuration name"
with the `--build' option; the host and target will default to be
the same as the build machine. (If you are building a
cross-compiler, see *Note Cross-Compiler::.)
Here is an example:
./configure --build=sparc-sun-sunos4.1
A configuration name may be canonical or it may be more or less
abbreviated.
A canonical configuration name has three parts, separated by
dashes. It looks like this: `CPU-COMPANY-SYSTEM'. (The three
parts may themselves contain dashes; `configure' can figure out
which dashes serve which purpose.) For example,
`m68k-sun-sunos4.1' specifies a Sun 3.
You can also replace parts of the configuration by nicknames or
aliases. For example, `sun3' stands for `m68k-sun', so
`sun3-sunos4.1' is another way to specify a Sun 3. You can also
use simply `sun3-sunos', since the version of SunOS is assumed by
default to be version 4. `sun3-bsd' also works, since `configure'
knows that the only BSD variant on a Sun 3 is SunOS.
You can specify a version number after any of the system types,
and some of the CPU types. In most cases, the version is
irrelevant, and will be ignored. So you might as well specify the
version if you know it.
See *Note Configurations::, for a list of supported configuration
names and notes on many of the configurations. You should check
the notes in that section before proceeding any further with the
installation of GNU CC.
There are four additional options you can specify independently to
describe variant hardware and software configurations. These are
`--with-gnu-as', `--with-gnu-ld', `--with-stabs' and `--nfp'.
`--with-gnu-as'
If you will use GNU CC with the GNU assembler (GAS), you
should declare this by using the `--with-gnu-as' option when
you run `configure'.
Using this option does not install GAS. It only modifies the
output of GNU CC to work with GAS. Building and installing
GAS is up to you.
Conversely, if you *do not* wish to use GAS and do not specify
`--with-gnu-as' when building GNU CC, it is up to you to make
sure that GAS is not installed. GNU CC searches for a
program named `as' in various directories; if the program it
finds is GAS, then it runs GAS. If you are not sure where
GNU CC finds the assembler it is using, try specifying `-v'
when you run it.
The systems where it makes a difference whether you use GAS
are
`hppa1.0-ANY-ANY', `hppa1.1-ANY-ANY', `i386-ANY-sysv',
`i386-ANY-isc',
`i860-ANY-bsd', `m68k-bull-sysv', `m68k-hp-hpux',
`m68k-sony-bsd',
`m68k-altos-sysv', `m68000-hp-hpux', `m68000-att-sysv',
`ANY-lynx-lynxos', and `mips-ANY'). On any other system,
`--with-gnu-as' has no effect.
On the systems listed above (except for the HP-PA, for ISC on
the 386, and for `mips-sgi-irix5.*'), if you use GAS, you
should also use the GNU linker (and specify `--with-gnu-ld').
`--with-gnu-ld'
Specify the option `--with-gnu-ld' if you plan to use the GNU
linker with GNU CC.
This option does not cause the GNU linker to be installed; it
just modifies the behavior of GNU CC to work with the GNU
linker. Specifically, it inhibits the installation of
`collect2', a program which otherwise serves as a front-end
for the system's linker on most configurations.
`--with-stabs'
On MIPS based systems and on Alphas, you must specify whether
you want GNU CC to create the normal ECOFF debugging format,
or to use BSD-style stabs passed through the ECOFF symbol
table. The normal ECOFF debug format cannot fully handle
languages other than C. BSD stabs format can handle other
languages, but it only works with the GNU debugger GDB.
Normally, GNU CC uses the ECOFF debugging format by default;
if you prefer BSD stabs, specify `--with-stabs' when you
configure GNU CC.
No matter which default you choose when you configure GNU CC,
the user can use the `-gcoff' and `-gstabs+' options to
specify explicitly the debug format for a particular
compilation.
`--with-stabs' is meaningful on the ISC system on the 386,
also, if `--with-gas' is used. It selects use of stabs
debugging information embedded in COFF output. This kind of
debugging information supports C++ well; ordinary COFF
debugging information does not.
`--with-stabs' is also meaningful on 386 systems running
SVR4. It selects use of stabs debugging information embedded
in ELF output. The C++ compiler currently (2.6.0) does not
support the DWARF debugging information normally used on 386
SVR4 platforms; stabs provide a workable alternative. This
requires gas and gdb, as the normal SVR4 tools can not
generate or interpret stabs.
`--nfp'
On certain systems, you must specify whether the machine has
a floating point unit. These systems include
`m68k-sun-sunosN' and `m68k-isi-bsd'. On any other system,
`--nfp' currently has no effect, though perhaps there are
other systems where it could usefully make a difference.
The `configure' script searches subdirectories of the source
directory for other compilers that are to be integrated into GNU
CC. The GNU compiler for C++, called G++ is in a subdirectory
named `cp'. `configure' inserts rules into `Makefile' to build
all of those compilers.
Here we spell out what files will be set up by `configure'.
Normally you need not be concerned with these files.
* A file named `config.h' is created that contains a `#include'
of the top-level config file for the machine you will run the
compiler on (*note The Configuration File:
(gcc.info)Config.). This file is responsible for defining
information about the host machine. It includes `tm.h'.
The top-level config file is located in the subdirectory
`config'. Its name is always `xm-SOMETHING.h'; usually
`xm-MACHINE.h', but there are some exceptions.
If your system does not support symbolic links, you might
want to set up `config.h' to contain a `#include' command
which refers to the appropriate file.
* A file named `tconfig.h' is created which includes the
top-level config file for your target machine. This is used
for compiling certain programs to run on that machine.
* A file named `tm.h' is created which includes the
machine-description macro file for your target machine. It
should be in the subdirectory `config' and its name is often
`MACHINE.h'.
* The command file `configure' also constructs the file
`Makefile' by adding some text to the template file
`Makefile.in'. The additional text comes from files in the
`config' directory, named `t-TARGET' and `x-HOST'. If these
files do not exist, it means nothing needs to be added for a
given target or host.
4. The standard directory for installing GNU CC is `/usr/local/lib'.
If you want to install its files somewhere else, specify
`--prefix=DIR' when you run `configure'. Here DIR is a directory
name to use instead of `/usr/local' for all purposes with one
exception: the directory `/usr/local/include' is searched for
header files no matter where you install the compiler. To override
this name, use the `--local-prefix' option below.
5. Specify `--local-prefix=DIR' if you want the compiler to search
directory `DIR/include' for locally installed header files
*instead* of `/usr/local/include'.
You should specify `--local-prefix' *only* if your site has a
different convention (not `/usr/local') for where to put
site-specific files.
*Do not* specify `/usr' as the `--local-prefix'! The directory
you use for `--local-prefix' *must not* contain any of the
system's standard header files. If it did contain them, certain
programs would be miscompiled (including GNU Emacs, on certain
targets), because this would override and nullify the header file
corrections made by the `fixincludes' script.
6. Make sure the Bison parser generator is installed. (This is
unnecessary if the Bison output files `c-parse.c' and `cexp.c' are
more recent than `c-parse.y' and `cexp.y' and you do not plan to
change the `.y' files.)
Bison versions older than Sept 8, 1988 will produce incorrect
output for `c-parse.c'.
7. If you have chosen a configuration for GNU CC which requires other
GNU tools (such as GAS or the GNU linker) instead of the standard
system tools, install the required tools in the build directory
under the names `as', `ld' or whatever is appropriate. This will
enable the compiler to find the proper tools for compilation of
the program `enquire'.
Alternatively, you can do subsequent compilation using a value of
the `PATH' environment variable such that the necessary GNU tools
come before the standard system tools.
8. Build the compiler. Just type `make LANGUAGES=c' in the compiler
directory.
`LANGUAGES=c' specifies that only the C compiler should be
compiled. The makefile normally builds compilers for all the
supported languages; currently, C, C++ and Objective C. However,
C is the only language that is sure to work when you build with
other non-GNU C compilers. In addition, building anything but C
at this stage is a waste of time.
In general, you can specify the languages to build by typing the
argument `LANGUAGES="LIST"', where LIST is one or more words from
the list `c', `c++', and `objective-c'. If you have any
additional GNU compilers as subdirectories of the GNU CC source
directory, you may also specify their names in this list.
Ignore any warnings you may see about "statement not reached" in
`insn-emit.c'; they are normal. Also, warnings about "unknown
escape sequence" are normal in `genopinit.c' and perhaps some
other files. Likewise, you should ignore warnings about "constant
is so large that it is unsigned" in `insn-emit.c' and
`insn-recog.c' and a warning about a comparison always being zero
in `enquire.o'. Any other compilation errors may represent bugs in
the port to your machine or operating system, and should be
investigated and reported.
Some commercial compilers fail to compile GNU CC because they have
bugs or limitations. For example, the Microsoft compiler is said
to run out of macro space. Some Ultrix compilers run out of
expression space; then you need to break up the statement where
the problem happens.
9. If you are building a cross-compiler, stop here. *Note
Cross-Compiler::.
10. Move the first-stage object files and executables into a
subdirectory with this command:
make stage1
The files are moved into a subdirectory named `stage1'. Once
installation is complete, you may wish to delete these files with
`rm -r stage1'.
11. If you have chosen a configuration for GNU CC which requires other
GNU tools (such as GAS or the GNU linker) instead of the standard
system tools, install the required tools in the `stage1'
subdirectory under the names `as', `ld' or whatever is
appropriate. This will enable the stage 1 compiler to find the
proper tools in the following stage.
Alternatively, you can do subsequent compilation using a value of
the `PATH' environment variable such that the necessary GNU tools
come before the standard system tools.
12. Recompile the compiler with itself, with this command:
make CC="stage1/xgcc -Bstage1/" CFLAGS="-g -O2"
This is called making the stage 2 compiler.
The command shown above builds compilers for all the supported
languages. If you don't want them all, you can specify the
languages to build by typing the argument `LANGUAGES="LIST"'. LIST
should contain one or more words from the list `c', `c++',
`objective-c', and `proto'. Separate the words with spaces.
`proto' stands for the programs `protoize' and `unprotoize'; they
are not a separate language, but you use `LANGUAGES' to enable or
disable their installation.
If you are going to build the stage 3 compiler, then you might
want to build only the C language in stage 2.
Once you have built the stage 2 compiler, if you are short of disk
space, you can delete the subdirectory `stage1'.
On a 68000 or 68020 system lacking floating point hardware, unless
you have selected a `tm.h' file that expects by default that there
is no such hardware, do this instead:
make CC="stage1/xgcc -Bstage1/" CFLAGS="-g -O2 -msoft-float"
13. If you wish to test the compiler by compiling it with itself one
more time, install any other necessary GNU tools (such as GAS or
the GNU linker) in the `stage2' subdirectory as you did in the
`stage1' subdirectory, then do this:
make stage2make CC="stage2/xgcc -Bstage2/" CFLAGS="-g -O2"
This is called making the stage 3 compiler. Aside from the `-B'
option, the compiler options should be the same as when you made
the stage 2 compiler. But the `LANGUAGES' option need not be the
same. The command shown above builds compilers for all the
supported languages; if you don't want them all, you can specify
the languages to build by typing the argument `LANGUAGES="LIST"',
as described above.
If you do not have to install any additional GNU tools, you may
use the command
make bootstrap LANGUAGES=LANGUAGE-LIST BOOT_CFLAGS=OPTION-LIST
instead of making `stage1', `stage2', and performing the two
compiler builds.
14. Then compare the latest object files with the stage 2 object
files--they ought to be identical, aside from time stamps (if any).
On some systems, meaningful comparison of object files is
impossible; they always appear "different." This is currently
true on Solaris and some systems that use ELF object file format.
On some versions of Irix on SGI machines and DEC Unix (OSF/1) on
Alpha systems, you will not be able to compare the files without
specifying `-save-temps'; see the description of individual
systems above to see if you get comparison failures. You may have
similar problems on other systems.
Use this command to compare the files:make compare
This will mention any object files that differ between stage 2 and
stage 3. Any difference, no matter how innocuous, indicates that
the stage 2 compiler has compiled GNU CC incorrectly, and is
therefore a potentially serious bug which you should investigate
and report.
If your system does not put time stamps in the object files, then
this is a faster way to compare them (using the Bourne shell):
for file in *.o; do
cmp $file stage2/$file
done
If you have built the compiler with the `-mno-mips-tfile' option on
MIPS machines, you will not be able to compare the files.
15. Install the compiler driver, the compiler's passes and run-time
support with `make install'. Use the same value for `CC',
`CFLAGS' and `LANGUAGES' that you used when compiling the files
that are being installed. One reason this is necessary is that
some versions of Make have bugs and recompile files gratuitously
when you do this step. If you use the same variable values, those
files will be recompiled properly.
For example, if you have built the stage 2 compiler, you can use
the following command:
make install CC="stage2/xgcc -Bstage2/" CFLAGS="-g -O" LANGUAGES="LIST"
This copies the files `cc1', `cpp' and `libgcc.a' to files `cc1',
`cpp' and `libgcc.a' in the directory
`/usr/local/lib/gcc-lib/TARGET/VERSION', which is where the
compiler driver program looks for them. Here TARGET is the target
machine type specified when you ran `configure', and VERSION is
the version number of GNU CC. This naming scheme permits various
versions and/or cross-compilers to coexist.
This also copies the driver program `xgcc' into
`/usr/local/bin/gcc', so that it appears in typical execution
search paths.
On some systems, this command causes recompilation of some files.
This is usually due to bugs in `make'. You should either ignore
this problem, or use GNU Make.
*Warning: there is a bug in `alloca' in the Sun library. To avoid
this bug, be sure to install the executables of GNU CC that were
compiled by GNU CC. (That is, the executables from stage 2 or 3,
not stage 1.) They use `alloca' as a built-in function and never
the one in the library.*
(It is usually better to install GNU CC executables from stage 2
or 3, since they usually run faster than the ones compiled with
some other compiler.)
16. If you're going to use C++, it's likely that you need to also
install the libg++ distribution. It should be available from the
same place where you got the GNU C distribution. Just as GNU C
does not distribute a C runtime library, it also does not include
a C++ run-time library. All I/O functionality, special class
libraries, etc., are available in the libg++ distribution.
Configurations Supported by GNU CC
==================================
Here are the possible CPU types:
1750a, a29k, alpha, arm, cN, clipper, dsp16xx, elxsi, h8300,
hppa1.0, hppa1.1, i370, i386, i486, i586, i860, i960, m68000, m68k,
m88k, mips, mipsel, mips64, mips64el, ns32k, powerpc, powerpcle,
pyramid, romp, rs6000, sh, sparc, sparclite, sparc64, vax, we32k.
Here are the recognized company names. As you can see, customary
abbreviations are used rather than the longer official names.
acorn, alliant, altos, apollo, att, bull, cbm, convergent, convex,
crds, dec, dg, dolphin, elxsi, encore, harris, hitachi, hp, ibm,
intergraph, isi, mips, motorola, ncr, next, ns, omron, plexus,
sequent, sgi, sony, sun, tti, unicom, wrs.
The company name is meaningful only to disambiguate when the rest of
the information supplied is insufficient. You can omit it, writing
just `CPU-SYSTEM', if it is not needed. For example, `vax-ultrix4.2'
is equivalent to `vax-dec-ultrix4.2'.
Here is a list of system types:
386bsd, aix, acis, amigados, aos, aout, bosx, bsd, clix, coff,
ctix, cxux, dgux, dynix, ebmon, ecoff, elf, esix, freebsd, hms,
genix, gnu, gnu/linux, hiux, hpux, iris, irix, isc, luna, lynxos,
mach, minix, msdos, mvs, netbsd, newsos, nindy, ns, osf, osfrose,
ptx, riscix, riscos, rtu, sco, sim, solaris, sunos, sym, sysv,
udi, ultrix, unicos, uniplus, unos, vms, vsta, vxworks, winnt,
xenix.
You can omit the system type; then `configure' guesses the operating
system from the CPU and company.
You can add a version number to the system type; this may or may not
make a difference. For example, you can write `bsd4.3' or `bsd4.4' to
distinguish versions of BSD. In practice, the version number is most
needed for `sysv3' and `sysv4', which are often treated differently.
If you specify an impossible combination such as `i860-dg-vms', then
you may get an error message from `configure', or it may ignore part of
the information and do the best it can with the rest. `configure'
always prints the canonical name for the alternative that it used. GNU
CC does not support all possible alternatives.
Often a particular model of machine has a name. Many machine names
are recognized as aliases for CPU/company combinations. Thus, the
machine name `sun3', mentioned above, is an alias for `m68k-sun'.
Sometimes we accept a company name as a machine name, when the name is
popularly used for a particular machine. Here is a table of the known
machine names:
3300, 3b1, 3bN, 7300, altos3068, altos, apollo68, att-7300,
balance, convex-cN, crds, decstation-3100, decstation, delta,
encore, fx2800, gmicro, hp7NN, hp8NN, hp9k2NN, hp9k3NN, hp9k7NN,
hp9k8NN, iris4d, iris, isi68, m3230, magnum, merlin, miniframe,
mmax, news-3600, news800, news, next, pbd, pc532, pmax, powerpc,
powerpcle, ps2, risc-news, rtpc, sun2, sun386i, sun386, sun3,
sun4, symmetry, tower-32, tower.
Remember that a machine name specifies both the cpu type and the company
name. If you want to install your own homemade configuration files,
you can use `local' as the company name to access them. If you use
configuration `CPU-local', the configuration name without the cpu prefix
is used to form the configuration file names.
Thus, if you specify `m68k-local', configuration uses files
`m68k.md', `local.h', `m68k.c', `xm-local.h', `t-local', and `x-local',
all in the directory `config/m68k'.
Here is a list of configurations that have special treatment or
special things you must know:
`1750a-*-*'
MIL-STD-1750A processors.
Starting with GCC 2.6.1, the MIL-STD-1750A cross configuration no
longer supports the Tektronix Assembler, but instead produces
output for `as1750', an assembler/linker available under the GNU
Public License for the 1750A. Contact *kellogg@space.otn.dasa.de*
for more details on obtaining `as1750'. A similarly licensed
simulator for the 1750A is available from same address.
You should ignore a fatal error during the building of libgcc
(libgcc is not yet implemented for the 1750A.)
The `as1750' assembler requires the file `ms1750.inc', which is
found in the directory `config/1750a'.
GNU CC produced the same sections as the Fairchild F9450 C
Compiler, namely:
`Normal'
The program code section.
`Static'
The read/write (RAM) data section.
`Konst'
The read-only (ROM) constants section.
`Init'
Initialization section (code to copy KREL to SREL).
The smallest addressable unit is 16 bits (BITS_PER_UNIT is 16).
This means that type `char' is represented with a 16-bit word per
character. The 1750A's "Load/Store Upper/Lower Byte" instructions
are not used by GNU CC.
`alpha-*-osf1'
Systems using processors that implement the DEC Alpha architecture
and are running the DEC Unix (OSF/1) operating system, for example
the DEC Alpha AXP systems. (VMS on the Alpha is not currently
supported by GNU CC.)
GNU CC writes a `.verstamp' directive to the assembler output file
unless it is built as a cross-compiler. It gets the version to
use from the system header file `/usr/include/stamp.h'. If you
install a new version of DEC Unix, you should rebuild GCC to pick
up the new version stamp.
Note that since the Alpha is a 64-bit architecture,
cross-compilers from 32-bit machines will not generate code as
efficient as that generated when the compiler is running on a
64-bit machine because many optimizations that depend on being
able to represent a word on the target in an integral value on the
host cannot be performed. Building cross-compilers on the Alpha
for 32-bit machines has only been tested in a few cases and may
not work properly.
`make compare' may fail on old versions of DEC Unix unless you add
`-save-temps' to `CFLAGS'. On these systems, the name of the
assembler input file is stored in the object file, and that makes
comparison fail if it differs between the `stage1' and `stage2'
compilations. The option `-save-temps' forces a fixed name to be
used for the assembler input file, instead of a randomly chosen
name in `/tmp'. Do not add `-save-temps' unless the comparisons
fail without that option. If you add `-save-temps', you will have
to manually delete the `.i' and `.s' files after each series of
compilations.
GNU CC now supports both the native (ECOFF) debugging format used
by DBX and GDB and an encapsulated STABS format for use only with
GDB. See the discussion of the `--with-stabs' option of
`configure' above for more information on these formats and how to
select them.
There is a bug in DEC's assembler that produces incorrect line
numbers for ECOFF format when the `.align' directive is used. To
work around this problem, GNU CC will not emit such alignment
directives while writing ECOFF format debugging information even
if optimization is being performed. Unfortunately, this has the
very undesirable side-effect that code addresses when `-O' is
specified are different depending on whether or not `-g' is also
specified.
To avoid this behavior, specify `-gstabs+' and use GDB instead of
DBX. DEC is now aware of this problem with the assembler and
hopes to provide a fix shortly.
`arm'
Advanced RISC Machines ARM-family processors. These are often
used in embedded applications. There are no standard Unix
configurations. This configuration corresponds to the basic
instruction sequences and will produce a.out format object modules.
You may need to make a variant of the file `arm.h' for your
particular configuration.
`arm-*-riscix'
The ARM2 or ARM3 processor running RISC iX, Acorn's port of BSD
Unix. If you are running a version of RISC iX prior to 1.2 then
you must specify the version number during configuration. Note
that the assembler shipped with RISC iX does not support stabs
debugging information; a new version of the assembler, with stabs
support included, is now available from Acorn.
`a29k'
AMD Am29k-family processors. These are normally used in embedded
applications. There are no standard Unix configurations. This
configuration corresponds to AMD's standard calling sequence and
binary interface and is compatible with other 29k tools.
You may need to make a variant of the file `a29k.h' for your
particular configuration.
`a29k-*-bsd'
AMD Am29050 used in a system running a variant of BSD Unix.
`decstation-*'
DECstations can support three different personalities: Ultrix, DEC
OSF/1, and OSF/rose. To configure GCC for these platforms use the
following configurations:
`decstation-ultrix'
Ultrix configuration.
`decstation-osf1'
Dec's version of OSF/1.
`decstation-osfrose'
Open Software Foundation reference port of OSF/1 which uses
the OSF/rose object file format instead of ECOFF. Normally,
you would not select this configuration.
The MIPS C compiler needs to be told to increase its table size
for switch statements with the `-Wf,-XNg1500' option in order to
compile `cp/parse.c'. If you use the `-O2' optimization option,
you also need to use `-Olimit 3000'. Both of these options are
automatically generated in the `Makefile' that the shell script
`configure' builds. If you override the `CC' make variable and
use the MIPS compilers, you may need to add `-Wf,-XNg1500 -Olimit
3000'.
`elxsi-elxsi-bsd'
The Elxsi's C compiler has known limitations that prevent it from
compiling GNU C. Please contact `mrs@cygnus.com' for more details.
`dsp16xx'
A port to the AT&T DSP1610 family of processors.
`h8300-*-*'
The calling convention and structure layout has changed in release
2.6. All code must be recompiled. The calling convention now
passes the first three arguments in function calls in registers.
Structures are no longer a multiple of 2 bytes.
`hppa*-*-*'
There are several variants of the HP-PA processor which run a
variety of operating systems. GNU CC must be configured to use
the correct processor type and operating system, or GNU CC will
not function correctly. The easiest way to handle this problem is
to *not* specify a target when configuring GNU CC, the `configure'
script will try to automatically determine the right processor
type and operating system.
`-g' does not work on HP-UX, since that system uses a peculiar
debugging format which GNU CC does not know about. However, `-g'
will work if you also use GAS and GDB in conjunction with GCC. We
highly recommend using GAS for all HP-PA configurations.
You should be using GAS-2.6 (or later) along with GDB-4.16 (or
later). These can be retrieved from all the traditional GNU ftp
archive sites.
GAS will need to be installed into a directory before `/bin',
`/usr/bin', and `/usr/ccs/bin' in your search path. You should
install GAS before you build GNU CC.
To enable debugging, you must configure GNU CC with the
`--with-gnu-as' option before building.
`i370-*-*'
This port is very preliminary and has many known bugs. We hope to
have a higher-quality port for this machine soon.
`i386-*-linuxoldld'
Use this configuration to generate a.out binaries on Linux-based
GNU systems, if you do not have gas/binutils version 2.5.2 or later
installed. This is an obsolete configuration.
`i386-*-linuxaout'
Use this configuration to generate a.out binaries on Linux-based
GNU systems. This configuration is being superseded. You must use
gas/binutils version 2.5.2 or later.
`i386-*-linux'
Use this configuration to generate ELF binaries on Linux-based GNU
systems. You must use gas/binutils version 2.5.2 or later.
`i386-*-sco'
Compilation with RCC is recommended. Also, it may be a good idea
to link with GNU malloc instead of the malloc that comes with the
system.
`i386-*-sco3.2v4'
Use this configuration for SCO release 3.2 version 4.
`i386-*-isc'
It may be a good idea to link with GNU malloc instead of the
malloc that comes with the system.
In ISC version 4.1, `sed' core dumps when building `deduced.h'.
Use the version of `sed' from version 4.0.
`i386-*-esix'
It may be good idea to link with GNU malloc instead of the malloc
that comes with the system.
`i386-ibm-aix'
You need to use GAS version 2.1 or later, and and LD from GNU
binutils version 2.2 or later.
`i386-sequent-bsd'
Go to the Berkeley universe before compiling. In addition, you
probably need to create a file named `string.h' containing just
one line: `#include <strings.h>'.
`i386-sequent-ptx1*'
Sequent DYNIX/ptx 1.x.
`i386-sequent-ptx2*'
Sequent DYNIX/ptx 2.x.
`i386-sun-sunos4'
You may find that you need another version of GNU CC to begin
bootstrapping with, since the current version when built with the
system's own compiler seems to get an infinite loop compiling part
of `libgcc2.c'. GNU CC version 2 compiled with GNU CC (any
version) seems not to have this problem.
See *Note Sun Install::, for information on installing GNU CC on
Sun systems.
`i[345]86-*-winnt3.5'
This version requires a GAS that has not let been released. Until
it is, you can get a prebuilt binary version via anonymous ftp from
`cs.washington.edu:pub/gnat' or `cs.nyu.edu:pub/gnat'. You must
also use the Microsoft header files from the Windows NT 3.5 SDK.
Find these on the CDROM in the `/mstools/h' directory dated
9/4/94. You must use a fixed version of Microsoft linker made
especially for NT 3.5, which is also is available on the NT 3.5
SDK CDROM. If you do not have this linker, can you also use the
linker from Visual C/C++ 1.0 or 2.0.
Installing GNU CC for NT builds a wrapper linker, called `ld.exe',
which mimics the behaviour of Unix `ld' in the specification of
libraries (`-L' and `-l'). `ld.exe' looks for both Unix and
Microsoft named libraries. For example, if you specify `-lfoo',
`ld.exe' will look first for `libfoo.a' and then for `foo.lib'.
You may install GNU CC for Windows NT in one of two ways,
depending on whether or not you have a Unix-like shell and various
Unix-like utilities.
1. If you do not have a Unix-like shell and few Unix-like
utilities, you will use a DOS style batch script called
`configure.bat'. Invoke it as `configure winnt' from an
MSDOS console window or from the program manager dialog box.
`configure.bat' assumes you have already installed and have
in your path a Unix-like `sed' program which is used to
create a working `Makefile' from `Makefile.in'.
`Makefile' uses the Microsoft Nmake program maintenance
utility and the Visual C/C++ V8.00 compiler to build GNU CC.
You need only have the utilities `sed' and `touch' to use
this installation method, which only automatically builds the
compiler itself. You must then examine what `fixinc.winnt'
does, edit the header files by hand and build `libgcc.a'
manually.
2. The second type of installation assumes you are running a
Unix-like shell, have a complete suite of Unix-like utilities
in your path, and have a previous version of GNU CC already
installed, either through building it via the above
installation method or acquiring a pre-built binary. In this
case, use the `configure' script in the normal fashion.
`i860-intel-osf1'
This is the Paragon. If you have version 1.0 of the operating
system, you need to take special steps to build GNU CC due to
peculiarities of the system. Newer system versions have no
problem. See the section `Installation Problems' in the GNU CC
Manual.
`*-lynx-lynxos'
LynxOS 2.2 and earlier comes with GNU CC 1.x already installed as
`/bin/gcc'. You should compile with this instead of `/bin/cc'.
You can tell GNU CC to use the GNU assembler and linker, by
specifying `--with-gnu-as --with-gnu-ld' when configuring. These
will produce COFF format object files and executables; otherwise
GNU CC will use the installed tools, which produce a.out format
executables.
`m68000-hp-bsd'
HP 9000 series 200 running BSD. Note that the C compiler that
comes with this system cannot compile GNU CC; contact
`law@cs.utah.edu' to get binaries of GNU CC for bootstrapping.
`m68k-altos'
Altos 3068. You must use the GNU assembler, linker and debugger.
Also, you must fix a kernel bug. Details in the file
`README.ALTOS'.
`m68k-att-sysv'
AT&T 3b1, a.k.a. 7300 PC. Special procedures are needed to
compile GNU CC with this machine's standard C compiler, due to
bugs in that compiler. You can bootstrap it more easily with
previous versions of GNU CC if you have them.
Installing GNU CC on the 3b1 is difficult if you do not already
have GNU CC running, due to bugs in the installed C compiler.
However, the following procedure might work. We are unable to
test it.
1. Comment out the `#include "config.h"' line on line 37 of
`cccp.c' and do `make cpp'. This makes a preliminary version
of GNU cpp.
2. Save the old `/lib/cpp' and copy the preliminary GNU cpp to
that file name.
3. Undo your change in `cccp.c', or reinstall the original
version, and do `make cpp' again.
4. Copy this final version of GNU cpp into `/lib/cpp'.
5. Replace every occurrence of `obstack_free' in the file
`tree.c' with `_obstack_free'.
6. Run `make' to get the first-stage GNU CC.
7. Reinstall the original version of `/lib/cpp'.
8. Now you can compile GNU CC with itself and install it in the
normal fashion.
`m68k-bull-sysv'
Bull DPX/2 series 200 and 300 with BOS-2.00.45 up to BOS-2.01. GNU
CC works either with native assembler or GNU assembler. You can use
GNU assembler with native coff generation by providing
`--with-gnu-as' to the configure script or use GNU assembler with
dbx-in-coff encapsulation by providing `--with-gnu-as --stabs'.
For any problem with native assembler or for availability of the
DPX/2 port of GAS, contact `F.Pierresteguy@frcl.bull.fr'.
`m68k-crds-unox'
Use `configure unos' for building on Unos.
The Unos assembler is named `casm' instead of `as'. For some
strange reason linking `/bin/as' to `/bin/casm' changes the
behavior, and does not work. So, when installing GNU CC, you
should install the following script as `as' in the subdirectory
where the passes of GCC are installed:
#!/bin/sh
casm $*
The default Unos library is named `libunos.a' instead of `libc.a'.
To allow GNU CC to function, either change all references to
`-lc' in `gcc.c' to `-lunos' or link `/lib/libc.a' to
`/lib/libunos.a'.
When compiling GNU CC with the standard compiler, to overcome bugs
in the support of `alloca', do not use `-O' when making stage 2.
Then use the stage 2 compiler with `-O' to make the stage 3
compiler. This compiler will have the same characteristics as the
usual stage 2 compiler on other systems. Use it to make a stage 4
compiler and compare that with stage 3 to verify proper
compilation.
(Perhaps simply defining `ALLOCA' in `x-crds' as described in the
comments there will make the above paragraph superfluous. Please
inform us of whether this works.)
Unos uses memory segmentation instead of demand paging, so you
will need a lot of memory. 5 Mb is barely enough if no other
tasks are running. If linking `cc1' fails, try putting the object
files into a library and linking from that library.
`m68k-hp-hpux'
HP 9000 series 300 or 400 running HP-UX. HP-UX version 8.0 has a
bug in the assembler that prevents compilation of GNU CC. To fix
it, get patch PHCO_4484 from HP.
In addition, if you wish to use gas `--with-gnu-as' you must use
gas version 2.1 or later, and you must use the GNU linker version
2.1 or later. Earlier versions of gas relied upon a program which
converted the gas output into the native HP/UX format, but that
program has not been kept up to date. gdb does not understand
that native HP/UX format, so you must use gas if you wish to use
gdb.
`m68k-sun'
Sun 3. We do not provide a configuration file to use the Sun FPA
by default, because programs that establish signal handlers for
floating point traps inherently cannot work with the FPA.
See *Note Sun Install::, for information on installing GNU CC on
Sun systems.
`m88k-*-svr3'
Motorola m88k running the AT&T/Unisoft/Motorola V.3 reference port.
These systems tend to use the Green Hills C, revision 1.8.5, as the
standard C compiler. There are apparently bugs in this compiler
that result in object files differences between stage 2 and stage
3. If this happens, make the stage 4 compiler and compare it to
the stage 3 compiler. If the stage 3 and stage 4 object files are
identical, this suggests you encountered a problem with the
standard C compiler; the stage 3 and 4 compilers may be usable.
It is best, however, to use an older version of GNU CC for
bootstrapping if you have one.
`m88k-*-dgux'
Motorola m88k running DG/UX. To build 88open BCS native or cross
compilers on DG/UX, specify the configuration name as
`m88k-*-dguxbcs' and build in the 88open BCS software development
environment. To build ELF native or cross compilers on DG/UX,
specify `m88k-*-dgux' and build in the DG/UX ELF development
environment. You set the software development environment by
issuing `sde-target' command and specifying either `m88kbcs' or
`m88kdguxelf' as the operand.
If you do not specify a configuration name, `configure' guesses the
configuration based on the current software development
environment.
`m88k-tektronix-sysv3'
Tektronix XD88 running UTekV 3.2e. Do not turn on optimization
while building stage1 if you bootstrap with the buggy Green Hills
compiler. Also, The bundled LAI System V NFS is buggy so if you
build in an NFS mounted directory, start from a fresh reboot, or
avoid NFS all together. Otherwise you may have trouble getting
clean comparisons between stages.
`mips-mips-bsd'
MIPS machines running the MIPS operating system in BSD mode. It's
possible that some old versions of the system lack the functions
`memcpy', `memcmp', and `memset'. If your system lacks these, you
must remove or undo the definition of `TARGET_MEM_FUNCTIONS' in
`mips-bsd.h'.
The MIPS C compiler needs to be told to increase its table size
for switch statements with the `-Wf,-XNg1500' option in order to
compile `cp/parse.c'. If you use the `-O2' optimization option,
you also need to use `-Olimit 3000'. Both of these options are
automatically generated in the `Makefile' that the shell script
`configure' builds. If you override the `CC' make variable and
use the MIPS compilers, you may need to add `-Wf,-XNg1500 -Olimit
3000'.
`mips-mips-riscos*'
The MIPS C compiler needs to be told to increase its table size
for switch statements with the `-Wf,-XNg1500' option in order to
compile `cp/parse.c'. If you use the `-O2' optimization option,
you also need to use `-Olimit 3000'. Both of these options are
automatically generated in the `Makefile' that the shell script
`configure' builds. If you override the `CC' make variable and
use the MIPS compilers, you may need to add `-Wf,-XNg1500 -Olimit
3000'.
MIPS computers running RISC-OS can support four different
personalities: default, BSD 4.3, System V.3, and System V.4 (older
versions of RISC-OS don't support V.4). To configure GCC for
these platforms use the following configurations:
`mips-mips-riscos`rev''
Default configuration for RISC-OS, revision `rev'.
`mips-mips-riscos`rev'bsd'
BSD 4.3 configuration for RISC-OS, revision `rev'.
`mips-mips-riscos`rev'sysv4'
System V.4 configuration for RISC-OS, revision `rev'.
`mips-mips-riscos`rev'sysv'
System V.3 configuration for RISC-OS, revision `rev'.
The revision `rev' mentioned above is the revision of RISC-OS to
use. You must reconfigure GCC when going from a RISC-OS revision
4 to RISC-OS revision 5. This has the effect of avoiding a linker
bug.
`mips-sgi-*'
In order to compile GCC on an SGI running IRIX 4, the "c.hdr.lib"
option must be installed from the CD-ROM supplied from Silicon
Graphics. This is found on the 2nd CD in release 4.0.1.
In order to compile GCC on an SGI running IRIX 5, the
"compiler_dev.hdr" subsystem must be installed from the IDO CD-ROM
supplied by Silicon Graphics.
`make compare' may fail on version 5 of IRIX unless you add
`-save-temps' to `CFLAGS'. On these systems, the name of the
assembler input file is stored in the object file, and that makes
comparison fail if it differs between the `stage1' and `stage2'
compilations. The option `-save-temps' forces a fixed name to be
used for the assembler input file, instead of a randomly chosen
name in `/tmp'. Do not add `-save-temps' unless the comparisons
fail without that option. If you do you `-save-temps', you will
have to manually delete the `.i' and `.s' files after each series
of compilations.
The MIPS C compiler needs to be told to increase its table size
for switch statements with the `-Wf,-XNg1500' option in order to
compile `cp/parse.c'. If you use the `-O2' optimization option,
you also need to use `-Olimit 3000'. Both of these options are
automatically generated in the `Makefile' that the shell script
`configure' builds. If you override the `CC' make variable and
use the MIPS compilers, you may need to add `-Wf,-XNg1500 -Olimit
3000'.
On Irix version 4.0.5F, and perhaps on some other versions as well,
there is an assembler bug that reorders instructions incorrectly.
To work around it, specify the target configuration
`mips-sgi-irix4loser'. This configuration inhibits assembler
optimization.
In a compiler configured with target `mips-sgi-irix4', you can turn
off assembler optimization by using the `-noasmopt' option. This
compiler option passes the option `-O0' to the assembler, to
inhibit reordering.
The `-noasmopt' option can be useful for testing whether a problem
is due to erroneous assembler reordering. Even if a problem does
not go away with `-noasmopt', it may still be due to assembler
reordering--perhaps GNU CC itself was miscompiled as a result.
To enable debugging under Irix 5, you must use GNU as 2.5 or later,
and use the `--with-gnu-as' configure option when configuring gcc.
GNU as is distributed as part of the binutils package.
`mips-sony-sysv'
Sony MIPS NEWS. This works in NEWSOS 5.0.1, but not in 5.0.2
(which uses ELF instead of COFF). Support for 5.0.2 will probably
be provided soon by volunteers. In particular, the linker does
not like the code generated by GCC when shared libraries are
linked in.
`ns32k-encore'
Encore ns32000 system. Encore systems are supported only under
BSD.
`ns32k-*-genix'
National Semiconductor ns32000 system. Genix has bugs in `alloca'
and `malloc'; you must get the compiled versions of these from GNU
Emacs.
`ns32k-sequent'
Go to the Berkeley universe before compiling. In addition, you
probably need to create a file named `string.h' containing just
one line: `#include <strings.h>'.
`ns32k-utek'
UTEK ns32000 system ("merlin"). The C compiler that comes with
this system cannot compile GNU CC; contact `tektronix!reed!mason'
to get binaries of GNU CC for bootstrapping.
`romp-*-aos'
`romp-*-mach'
The only operating systems supported for the IBM RT PC are AOS and
MACH. GNU CC does not support AIX running on the RT. We
recommend you compile GNU CC with an earlier version of itself; if
you compile GNU CC with `hc', the Metaware compiler, it will work,
but you will get mismatches between the stage 2 and stage 3
compilers in various files. These errors are minor differences in
some floating-point constants and can be safely ignored; the stage
3 compiler is correct.
`rs6000-*-aix'
`powerpc-*-aix'
Various early versions of each release of the IBM XLC compiler
will not bootstrap GNU CC. Symptoms include differences between
the stage2 and stage3 object files, and errors when compiling
`libgcc.a' or `enquire'. Known problematic releases include:
xlc-1.2.1.8, xlc-1.3.0.0 (distributed with AIX 3.2.5), and
xlc-1.3.0.19. Both xlc-1.2.1.28 and xlc-1.3.0.24 (PTF 432238) are
known to produce working versions of GNU CC, but most other recent
releases correctly bootstrap GNU CC. Also, releases of AIX prior
to AIX 3.2.4 include a version of the IBM assembler which does not
accept debugging directives: assembler updates are available as
PTFs. Also, if you are using AIX 3.2.5 or greater and the GNU
assembler, you must have a version modified after October 16th,
1995 in order for the GNU C compiler to build. See the file
`README.RS6000' for more details on of these problems.
GNU CC does not yet support the 64-bit PowerPC instructions.
Objective C does not work on this architecture because it makes
assumptions that are incompatible with the calling conventions.
AIX on the RS/6000 provides support (NLS) for environments outside
of the United States. Compilers and assemblers use NLS to support
locale-specific representations of various objects including
floating-point numbers ("." vs "," for separating decimal
fractions). There have been problems reported where the library
linked with GNU CC does not produce the same floating-point
formats that the assembler accepts. If you have this problem, set
the LANG environment variable to "C" or "En_US".
Due to changes in the way that GNU CC invokes the binder (linker)
for AIX 4.1, you may now receive warnings of duplicate symbols
from the link step that were not reported before. The assembly
files generated by GNU CC for AIX have always included multiple
symbol definitions for certain global variable and function
declarations in the original program. The warnings should not
prevent the linker from producing a correct library or runnable
executable.
`powerpc-*-elf'
`powerpc-*-sysv4'
PowerPC system in big endian mode, running System V.4.
This configuration is currently under development.
`powerpc-*-eabiaix'
Embedded PowerPC system in big endian mode with -mcall-aix
selected as the default. This system is currently under
development.
`powerpc-*-eabisim'
Embedded PowerPC system in big endian mode for use in running
under the PSIM simulator. This system is currently under
development.
`powerpc-*-eabi'
Embedded PowerPC system in big endian mode.
This configuration is currently under development.
`powerpcle-*-elf'
`powerpcle-*-sysv4'
PowerPC system in little endian mode, running System V.4.
This configuration is currently under development.
`powerpcle-*-sysv4'
Embedded PowerPC system in little endian mode.
This system is currently under development.
`powerpcle-*-eabisim'
Embedded PowerPC system in little endian mode for use in running
under the PSIM simulator.
This system is currently under development.
`powerpcle-*-eabi'
Embedded PowerPC system in little endian mode.
This configuration is currently under development.
`vax-dec-ultrix'
Don't try compiling with Vax C (`vcc'). It produces incorrect code
in some cases (for example, when `alloca' is used).
Meanwhile, compiling `cp/parse.c' with pcc does not work because of
an internal table size limitation in that compiler. To avoid this
problem, compile just the GNU C compiler first, and use it to
recompile building all the languages that you want to run.
`sparc-sun-*'
See *Note Sun Install::, for information on installing GNU CC on
Sun systems.
`vax-dec-vms'
See *Note VMS Install::, for details on how to install GNU CC on
VMS.
`we32k-*-*'
These computers are also known as the 3b2, 3b5, 3b20 and other
similar names. (However, the 3b1 is actually a 68000; see *Note
Configurations::.)
Don't use `-g' when compiling with the system's compiler. The
system's linker seems to be unable to handle such a large program
with debugging information.
The system's compiler runs out of capacity when compiling `stmt.c'
in GNU CC. You can work around this by building `cpp' in GNU CC
first, then use that instead of the system's preprocessor with the
system's C compiler to compile `stmt.c'. Here is how:
mv /lib/cpp /lib/cpp.att
cp cpp /lib/cpp.gnu
echo '/lib/cpp.gnu -traditional ${1+"$@"}' > /lib/cpp
chmod +x /lib/cpp
The system's compiler produces bad code for some of the GNU CC
optimization files. So you must build the stage 2 compiler without
optimization. Then build a stage 3 compiler with optimization.
That executable should work. Here are the necessary commands:
make LANGUAGES=c CC=stage1/xgcc CFLAGS="-Bstage1/ -g"
make stage2
make CC=stage2/xgcc CFLAGS="-Bstage2/ -g -O"
You may need to raise the ULIMIT setting to build a C++ compiler,
as the file `cc1plus' is larger than one megabyte.
Compilation in a Separate Directory
===================================
If you wish to build the object files and executables in a directory
other than the one containing the source files, here is what you must
do differently:
1. Make sure you have a version of Make that supports the `VPATH'
feature. (GNU Make supports it, as do Make versions on most BSD
systems.)
2. If you have ever run `configure' in the source directory, you must
undo the configuration. Do this by running:
make distclean
3. Go to the directory in which you want to build the compiler before
running `configure':
mkdir gcc-sun3
cd gcc-sun3
On systems that do not support symbolic links, this directory must
be on the same file system as the source code directory.
4. Specify where to find `configure' when you run it:
../gcc/configure ...
This also tells `configure' where to find the compiler sources;
`configure' takes the directory from the file name that was used to
invoke it. But if you want to be sure, you can specify the source
directory with the `--srcdir' option, like this:
../gcc/configure --srcdir=../gcc OTHER OPTIONS
The directory you specify with `--srcdir' need not be the same as
the one that `configure' is found in.
Now, you can run `make' in that directory. You need not repeat the
configuration steps shown above, when ordinary source files change. You
must, however, run `configure' again when the configuration files
change, if your system does not support symbolic links.
Building and Installing a Cross-Compiler
========================================
GNU CC can function as a cross-compiler for many machines, but not
all.
* Cross-compilers for the Mips as target using the Mips assembler
currently do not work, because the auxiliary programs
`mips-tdump.c' and `mips-tfile.c' can't be compiled on anything
but a Mips. It does work to cross compile for a Mips if you use
the GNU assembler and linker.
* Cross-compilers between machines with different floating point
formats have not all been made to work. GNU CC now has a floating
point emulator with which these can work, but each target machine
description needs to be updated to take advantage of it.
* Cross-compilation between machines of different word sizes is
somewhat problematic and sometimes does not work.
Since GNU CC generates assembler code, you probably need a
cross-assembler that GNU CC can run, in order to produce object files.
If you want to link on other than the target machine, you need a
cross-linker as well. You also need header files and libraries suitable
for the target machine that you can install on the host machine.
Steps of Cross-Compilation
--------------------------
To compile and run a program using a cross-compiler involves several
steps:
* Run the cross-compiler on the host machine to produce assembler
files for the target machine. This requires header files for the
target machine.
* Assemble the files produced by the cross-compiler. You can do this
either with an assembler on the target machine, or with a
cross-assembler on the host machine.
* Link those files to make an executable. You can do this either
with a linker on the target machine, or with a cross-linker on the
host machine. Whichever machine you use, you need libraries and
certain startup files (typically `crt....o') for the target
machine.
It is most convenient to do all of these steps on the same host
machine, since then you can do it all with a single invocation of GNU
CC. This requires a suitable cross-assembler and cross-linker. For
some targets, the GNU assembler and linker are available.
Configuring a Cross-Compiler
----------------------------
To build GNU CC as a cross-compiler, you start out by running
`configure'. Use the `--target=TARGET' to specify the target type. If
`configure' was unable to correctly identify the system you are running
on, also specify the `--build=BUILD' option. For example, here is how
to configure for a cross-compiler that produces code for an HP 68030
system running BSD on a system that `configure' can correctly identify:
./configure --target=m68k-hp-bsd4.3
Tools and Libraries for a Cross-Compiler
----------------------------------------
If you have a cross-assembler and cross-linker available, you should
install them now. Put them in the directory `/usr/local/TARGET/bin'.
Here is a table of the tools you should put in this directory:
`as'
This should be the cross-assembler.
`ld'
This should be the cross-linker.
`ar'
This should be the cross-archiver: a program which can manipulate
archive files (linker libraries) in the target machine's format.
`ranlib'
This should be a program to construct a symbol table in an archive
file.
The installation of GNU CC will find these programs in that
directory, and copy or link them to the proper place to for the
cross-compiler to find them when run later.
The easiest way to provide these files is to build the Binutils
package and GAS. Configure them with the same `--host' and `--target'
options that you use for configuring GNU CC, then build and install
them. They install their executables automatically into the proper
directory. Alas, they do not support all the targets that GNU CC
supports.
If you want to install libraries to use with the cross-compiler,
such as a standard C library, put them in the directory
`/usr/local/TARGET/lib'; installation of GNU CC copies all all the
files in that subdirectory into the proper place for GNU CC to find
them and link with them. Here's an example of copying some libraries
from a target machine:
ftp TARGET-MACHINE
lcd /usr/local/TARGET/lib
cd /lib
get libc.a
cd /usr/lib
get libg.a
get libm.a
quit
The precise set of libraries you'll need, and their locations on the
target machine, vary depending on its operating system.
Many targets require "start files" such as `crt0.o' and `crtn.o'
which are linked into each executable; these too should be placed in
`/usr/local/TARGET/lib'. There may be several alternatives for
`crt0.o', for use with profiling or other compilation options. Check
your target's definition of `STARTFILE_SPEC' to find out what start
files it uses. Here's an example of copying these files from a target
machine:
ftp TARGET-MACHINE
lcd /usr/local/TARGET/lib
prompt
cd /lib
mget *crt*.o
cd /usr/lib
mget *crt*.o
quit
`libgcc.a' and Cross-Compilers
------------------------------
Code compiled by GNU CC uses certain runtime support functions
implicitly. Some of these functions can be compiled successfully with
GNU CC itself, but a few cannot be. These problem functions are in the
source file `libgcc1.c'; the library made from them is called
`libgcc1.a'.
When you build a native compiler, these functions are compiled with
some other compiler-the one that you use for bootstrapping GNU CC.
Presumably it knows how to open code these operations, or else knows how
to call the run-time emulation facilities that the machine comes with.
But this approach doesn't work for building a cross-compiler. The
compiler that you use for building knows about the host system, not the
target system.
So, when you build a cross-compiler you have to supply a suitable
library `libgcc1.a' that does the job it is expected to do.
To compile `libgcc1.c' with the cross-compiler itself does not work.
The functions in this file are supposed to implement arithmetic
operations that GNU CC does not know how to open code for your target
machine. If these functions are compiled with GNU CC itself, they will
compile into infinite recursion.
On any given target, most of these functions are not needed. If GNU
CC can open code an arithmetic operation, it will not call these
functions to perform the operation. It is possible that on your target
machine, none of these functions is needed. If so, you can supply an
empty library as `libgcc1.a'.
Many targets need library support only for multiplication and
division. If you are linking with a library that contains functions for
multiplication and division, you can tell GNU CC to call them directly
by defining the macros `MULSI3_LIBCALL', and the like. These macros
need to be defined in the target description macro file. For some
targets, they are defined already. This may be sufficient to avoid the
need for libgcc1.a; if so, you can supply an empty library.
Some targets do not have floating point instructions; they need other
functions in `libgcc1.a', which do floating arithmetic. Recent
versions of GNU CC have a file which emulates floating point. With a
certain amount of work, you should be able to construct a floating
point emulator that can be used as `libgcc1.a'. Perhaps future
versions will contain code to do this automatically and conveniently.
That depends on whether someone wants to implement it.
Some embedded targets come with all the necessary `libgcc1.a'
routines written in C or assembler. These targets build `libgcc1.a'
automatically and you do not need to do anything special for them.
Other embedded targets do not need any `libgcc1.a' routines since all
the necessary operations are supported by the hardware.
If your target system has another C compiler, you can configure GNU
CC as a native compiler on that machine, build just `libgcc1.a' with
`make libgcc1.a' on that machine, and use the resulting file with the
cross-compiler. To do this, execute the following on the target
machine:
cd TARGET-BUILD-DIR
./configure --host=sparc --target=sun3
make libgcc1.a
And then this on the host machine:
ftp TARGET-MACHINE
binary
cd TARGET-BUILD-DIR
get libgcc1.a
quit
Another way to provide the functions you need in `libgcc1.a' is to
define the appropriate `perform_...' macros for those functions. If
these definitions do not use the C arithmetic operators that they are
meant to implement, you should be able to compile them with the
cross-compiler you are building. (If these definitions already exist
for your target file, then you are all set.)
To build `libgcc1.a' using the perform macros, use
`LIBGCC1=libgcc1.a OLDCC=./xgcc' when building the compiler.
Otherwise, you should place your replacement library under the name
`libgcc1.a' in the directory in which you will build the
cross-compiler, before you run `make'.
Cross-Compilers and Header Files
--------------------------------
If you are cross-compiling a standalone program or a program for an
embedded system, then you may not need any header files except the few
that are part of GNU CC (and those of your program). However, if you
intend to link your program with a standard C library such as `libc.a',
then you probably need to compile with the header files that go with
the library you use.
The GNU C compiler does not come with these files, because (1) they
are system-specific, and (2) they belong in a C library, not in a
compiler.
If the GNU C library supports your target machine, then you can get
the header files from there (assuming you actually use the GNU library
when you link your program).
If your target machine comes with a C compiler, it probably comes
with suitable header files also. If you make these files accessible
from the host machine, the cross-compiler can use them also.
Otherwise, you're on your own in finding header files to use when
cross-compiling.
When you have found suitable header files, put them in
`/usr/local/TARGET/include', before building the cross compiler. Then
installation will run fixincludes properly and install the corrected
versions of the header files where the compiler will use them.
Provide the header files before you build the cross-compiler, because
the build stage actually runs the cross-compiler to produce parts of
`libgcc.a'. (These are the parts that *can* be compiled with GNU CC.)
Some of them need suitable header files.
Here's an example showing how to copy the header files from a target
machine. On the target machine, do this:
(cd /usr/include; tar cf - .) > tarfile
Then, on the host machine, do this:
ftp TARGET-MACHINE
lcd /usr/local/TARGET/include
get tarfile
quit
tar xf tarfile
Actually Building the Cross-Compiler
------------------------------------
Now you can proceed just as for compiling a single-machine compiler
through the step of building stage 1. If you have not provided some
sort of `libgcc1.a', then compilation will give up at the point where
it needs that file, printing a suitable error message. If you do
provide `libgcc1.a', then building the compiler will automatically
compile and link a test program called `libgcc1-test'; if you get
errors in the linking, it means that not all of the necessary routines
in `libgcc1.a' are available.
You must provide the header file `float.h'. One way to do this is
to compile `enquire' and run it on your target machine. The job of
`enquire' is to run on the target machine and figure out by experiment
the nature of its floating point representation. `enquire' records its
findings in the header file `float.h'. If you can't produce this file
by running `enquire' on the target machine, then you will need to come
up with a suitable `float.h' in some other way (or else, avoid using it
in your programs).
Do not try to build stage 2 for a cross-compiler. It doesn't work to
rebuild GNU CC as a cross-compiler using the cross-compiler, because
that would produce a program that runs on the target machine, not on the
host. For example, if you compile a 386-to-68030 cross-compiler with
itself, the result will not be right either for the 386 (because it was
compiled into 68030 code) or for the 68030 (because it was configured
for a 386 as the host). If you want to compile GNU CC into 68030 code,
whether you compile it on a 68030 or with a cross-compiler on a 386, you
must specify a 68030 as the host when you configure it.
To install the cross-compiler, use `make install', as usual.
Installing GNU CC on the Sun
============================
On Solaris (version 2.1), do not use the linker or other tools in
`/usr/ucb' to build GNU CC. Use `/usr/ccs/bin'.
Make sure the environment variable `FLOAT_OPTION' is not set when
you compile `libgcc.a'. If this option were set to `f68881' when
`libgcc.a' is compiled, the resulting code would demand to be linked
with a special startup file and would not link properly without special
pains.
There is a bug in `alloca' in certain versions of the Sun library.
To avoid this bug, install the binaries of GNU CC that were compiled by
GNU CC. They use `alloca' as a built-in function and never the one in
the library.
Some versions of the Sun compiler crash when compiling GNU CC. The
problem is a segmentation fault in cpp. This problem seems to be due to
the bulk of data in the environment variables. You may be able to avoid
it by using the following command to compile GNU CC with Sun CC:
make CC="TERMCAP=x OBJS=x LIBFUNCS=x STAGESTUFF=x cc"
Installing GNU CC on VMS
========================
The VMS version of GNU CC is distributed in a backup saveset
containing both source code and precompiled binaries.
To install the `gcc' command so you can use the compiler easily, in
the same manner as you use the VMS C compiler, you must install the VMS
CLD file for GNU CC as follows:
1. Define the VMS logical names `GNU_CC' and `GNU_CC_INCLUDE' to
point to the directories where the GNU CC executables
(`gcc-cpp.exe', `gcc-cc1.exe', etc.) and the C include files are
kept respectively. This should be done with the commands:
$ assign /system /translation=concealed -
disk:[gcc.] gnu_cc
$ assign /system /translation=concealed -
disk:[gcc.include.] gnu_cc_include
with the appropriate disk and directory names. These commands can
be placed in your system startup file so they will be executed
whenever the machine is rebooted. You may, if you choose, do this
via the `GCC_INSTALL.COM' script in the `[GCC]' directory.
2. Install the `GCC' command with the command line:
$ set command /table=sys$common:[syslib]dcltables -
/output=sys$common:[syslib]dcltables gnu_cc:[000000]gcc
$ install replace sys$common:[syslib]dcltables
3. To install the help file, do the following:
$ library/help sys$library:helplib.hlb gcc.hlp
Now you can invoke the compiler with a command like `gcc /verbose
file.c', which is equivalent to the command `gcc -v -c file.c' in
Unix.
If you wish to use GNU C++ you must first install GNU CC, and then
perform the following steps:
1. Define the VMS logical name `GNU_GXX_INCLUDE' to point to the
directory where the preprocessor will search for the C++ header
files. This can be done with the command:
$ assign /system /translation=concealed -
disk:[gcc.gxx_include.] gnu_gxx_include
with the appropriate disk and directory name. If you are going to
be using libg++, this is where the libg++ install procedure will
install the libg++ header files.
2. Obtain the file `gcc-cc1plus.exe', and place this in the same
directory that `gcc-cc1.exe' is kept.
The GNU C++ compiler can be invoked with a command like `gcc /plus
/verbose file.cc', which is equivalent to the command `g++ -v -c
file.cc' in Unix.
We try to put corresponding binaries and sources on the VMS
distribution tape. But sometimes the binaries will be from an older
version than the sources, because we don't always have time to update
them. (Use the `/version' option to determine the version number of
the binaries and compare it with the source file `version.c' to tell
whether this is so.) In this case, you should use the binaries you get
to recompile the sources. If you must recompile, here is how:
1. Execute the command procedure `vmsconfig.com' to set up the files
`tm.h', `config.h', `aux-output.c', and `md.', and to create files
`tconfig.h' and `hconfig.h'. This procedure also creates several
linker option files used by `make-cc1.com' and a data file used by
`make-l2.com'.
$ @vmsconfig.com
2. Setup the logical names and command tables as defined above. In
addition, define the VMS logical name `GNU_BISON' to point at the
to the directories where the Bison executable is kept. This
should be done with the command:
$ assign /system /translation=concealed -
disk:[bison.] gnu_bison
You may, if you choose, use the `INSTALL_BISON.COM' script in the
`[BISON]' directory.
3. Install the `BISON' command with the command line:
$ set command /table=sys$common:[syslib]dcltables -
/output=sys$common:[syslib]dcltables -
gnu_bison:[000000]bison
$ install replace sys$common:[syslib]dcltables
4. Type `@make-gcc' to recompile everything (alternatively, submit
the file `make-gcc.com' to a batch queue). If you wish to build
the GNU C++ compiler as well as the GNU CC compiler, you must
first edit `make-gcc.com' and follow the instructions that appear
in the comments.
5. In order to use GCC, you need a library of functions which GCC
compiled code will call to perform certain tasks, and these
functions are defined in the file `libgcc2.c'. To compile this
you should use the command procedure `make-l2.com', which will
generate the library `libgcc2.olb'. `libgcc2.olb' should be built
using the compiler built from the same distribution that
`libgcc2.c' came from, and `make-gcc.com' will automatically do
all of this for you.
To install the library, use the following commands:
$ library gnu_cc:[000000]gcclib/delete=(new,eprintf)
$ library gnu_cc:[000000]gcclib/delete=L_*
$ library libgcc2/extract=*/output=libgcc2.obj
$ library gnu_cc:[000000]gcclib libgcc2.obj
The first command simply removes old modules that will be replaced
with modules from `libgcc2' under different module names. The
modules `new' and `eprintf' may not actually be present in your
`gcclib.olb'--if the VMS librarian complains about those modules
not being present, simply ignore the message and continue on with
the next command. The second command removes the modules that
came from the previous version of the library `libgcc2.c'.
Whenever you update the compiler on your system, you should also
update the library with the above procedure.
6. You may wish to build GCC in such a way that no files are written
to the directory where the source files reside. An example would
be the when the source files are on a read-only disk. In these
cases, execute the following DCL commands (substituting your
actual path names):
$ assign dua0:[gcc.build_dir.]/translation=concealed, -
dua1:[gcc.source_dir.]/translation=concealed gcc_build
$ set default gcc_build:[000000]
where the directory `dua1:[gcc.source_dir]' contains the source
code, and the directory `dua0:[gcc.build_dir]' is meant to contain
all of the generated object files and executables. Once you have
done this, you can proceed building GCC as described above. (Keep
in mind that `gcc_build' is a rooted logical name, and thus the
device names in each element of the search list must be an actual
physical device name rather than another rooted logical name).
7. *If you are building GNU CC with a previous version of GNU CC, you
also should check to see that you have the newest version of the
assembler*. In particular, GNU CC version 2 treats global constant
variables slightly differently from GNU CC version 1, and GAS
version 1.38.1 does not have the patches required to work with GCC
version 2. If you use GAS 1.38.1, then `extern const' variables
will not have the read-only bit set, and the linker will generate
warning messages about mismatched psect attributes for these
variables. These warning messages are merely a nuisance, and can
safely be ignored.
If you are compiling with a version of GNU CC older than 1.33,
specify `/DEFINE=("inline=")' as an option in all the
compilations. This requires editing all the `gcc' commands in
`make-cc1.com'. (The older versions had problems supporting
`inline'.) Once you have a working 1.33 or newer GNU CC, you can
change this file back.
8. If you want to build GNU CC with the VAX C compiler, you will need
to make minor changes in `make-cccp.com' and `make-cc1.com' to
choose alternate definitions of `CC', `CFLAGS', and `LIBS'. See
comments in those files. However, you must also have a working
version of the GNU assembler (GNU as, aka GAS) as it is used as
the back-end for GNU CC to produce binary object modules and is
not included in the GNU CC sources. GAS is also needed to compile
`libgcc2' in order to build `gcclib' (see above); `make-l2.com'
expects to be able to find it operational in
`gnu_cc:[000000]gnu-as.exe'.
To use GNU CC on VMS, you need the VMS driver programs `gcc.exe',
`gcc.com', and `gcc.cld'. They are distributed with the VMS
binaries (`gcc-vms') rather than the GNU CC sources. GAS is also
included in `gcc-vms', as is Bison.
Once you have successfully built GNU CC with VAX C, you should use
the resulting compiler to rebuild itself. Before doing this, be
sure to restore the `CC', `CFLAGS', and `LIBS' definitions in
`make-cccp.com' and `make-cc1.com'. The second generation
compiler will be able to take advantage of many optimizations that
must be suppressed when building with other compilers.
Under previous versions of GNU CC, the generated code would
occasionally give strange results when linked with the sharable
`VAXCRTL' library. Now this should work.
Even with this version, however, GNU CC itself should not be linked
with the sharable `VAXCRTL'. The version of `qsort' in `VAXCRTL' has a
bug (known to be present in VMS versions V4.6 through V5.5) which
causes the compiler to fail.
The executables are generated by `make-cc1.com' and `make-cccp.com'
use the object library version of `VAXCRTL' in order to make use of the
`qsort' routine in `gcclib.olb'. If you wish to link the compiler
executables with the shareable image version of `VAXCRTL', you should
edit the file `tm.h' (created by `vmsconfig.com') to define the macro
`QSORT_WORKAROUND'.
`QSORT_WORKAROUND' is always defined when GNU CC is compiled with
VAX C, to avoid a problem in case `gcclib.olb' is not yet available.
`collect2'
==========
Many target systems do not have support in the assembler and linker
for "constructors"--initialization functions to be called before the
official "start" of `main'. On such systems, GNU CC uses a utility
called `collect2' to arrange to call these functions at start time.
The program `collect2' works by linking the program once and looking
through the linker output file for symbols with particular names
indicating they are constructor functions. If it finds any, it creates
a new temporary `.c' file containing a table of them, compiles it, and
links the program a second time including that file.
The actual calls to the constructors are carried out by a subroutine
called `__main', which is called (automatically) at the beginning of
the body of `main' (provided `main' was compiled with GNU CC). Calling
`__main' is necessary, even when compiling C code, to allow linking C
and C++ object code together. (If you use `-nostdlib', you get an
unresolved reference to `__main', since it's defined in the standard
GCC library. Include `-lgcc' at the end of your compiler command line
to resolve this reference.)
The program `collect2' is installed as `ld' in the directory where
the passes of the compiler are installed. When `collect2' needs to
find the *real* `ld', it tries the following file names:
* `real-ld' in the directories listed in the compiler's search
directories.
* `real-ld' in the directories listed in the environment variable
`PATH'.
* The file specified in the `REAL_LD_FILE_NAME' configuration macro,
if specified.
* `ld' in the compiler's search directories, except that `collect2'
will not execute itself recursively.
* `ld' in `PATH'.
"The compiler's search directories" means all the directories where
`gcc' searches for passes of the compiler. This includes directories
that you specify with `-B'.
Cross-compilers search a little differently:
* `real-ld' in the compiler's search directories.
* `TARGET-real-ld' in `PATH'.
* The file specified in the `REAL_LD_FILE_NAME' configuration macro,
if specified.
* `ld' in the compiler's search directories.
* `TARGET-ld' in `PATH'.
`collect2' explicitly avoids running `ld' using the file name under
which `collect2' itself was invoked. In fact, it remembers up a list
of such names--in case one copy of `collect2' finds another copy (or
version) of `collect2' installed as `ld' in a second place in the
search path.
`collect2' searches for the utilities `nm' and `strip' using the
same algorithm as above for `ld'.
Standard Header File Directories
================================
`GCC_INCLUDE_DIR' means the same thing for native and cross. It is
where GNU CC stores its private include files, and also where GNU CC
stores the fixed include files. A cross compiled GNU CC runs
`fixincludes' on the header files in `$(tooldir)/include'. (If the
cross compilation header files need to be fixed, they must be installed
before GNU CC is built. If the cross compilation header files are
already suitable for ANSI C and GNU CC, nothing special need be done).
`GPLUS_INCLUDE_DIR' means the same thing for native and cross. It
is where `g++' looks first for header files. `libg++' installs only
target independent header files in that directory.
`LOCAL_INCLUDE_DIR' is used only for a native compiler. It is
normally `/usr/local/include'. GNU CC searches this directory so that
users can install header files in `/usr/local/include'.
`CROSS_INCLUDE_DIR' is used only for a cross compiler. GNU CC
doesn't install anything there.
`TOOL_INCLUDE_DIR' is used for both native and cross compilers. It
is the place for other packages to install header files that GNU CC will
use. For a cross-compiler, this is the equivalent of `/usr/include'.
When you build a cross-compiler, `fixincludes' processes any header
files in this directory.